A known fuel pump includes an impeller, which is rotational inside a pump chamber, and a motor portion, which drives the impeller. The fuel pump press-feeds fuel in a fuel tank into an internal combustion engine by utilizing rotation of the impeller. Patent Document 1 discloses a fuel pump equipped with a motor portion, which includes a stator and a rotor. The stator is equipped with a winding. The rotor is equipped on the radially inside of the stator and connected to the impeller via a shaft.
(Patent Document 1)
Publication of unexamined Japanese patent application No. 2012-228178
The fuel pump disclosed in Patent Document 1 has multiple ribs on the radially outside of the stator in order to align the center axis of the stator relative to the center axis of the housing, which accommodate the stator. The ribs are formed in consideration of a press-fitting margin of the stator relative to the housing. In a manufacturing process of the fuel pump disclosed in Patent Document 1, the stator is press-fitted into the tubular housing, such that the multiple ribs make contact to the inner wall of the housing in uniform. In the present state, the multiple ribs are slid on the inner wall of the housing. Therefore, the ribs may deform due to burr and/or a plucking. Consequently, the position of the stator may be shifted relative to the position of the housing. Thus, alignment between the center axis housing and the center axis of the stator may be made at low accuracy.